Terms used on compound pages, in trial reports and in community slang. Links go to the page where the term matters most.
A
Agonist: A molecule that binds a receptor and switches it on. Semaglutide is a GLP-1 receptor agonist; it activates the same receptor as the natural hormone.
Albumin binding: A way of stretching a peptide's half-life by making it stick to albumin, the most abundant protein in blood. Semaglutide uses a fatty-acid chain to do this; CJC-1295 with DAC uses a chemical anchor.
Amino acid: The building block of peptides and proteins. Twenty standard amino acids, linked in a chain, make up every peptide on this site.
Amylin: A hormone released with insulin that slows stomach emptying and signals fullness. Cagrilintide is a long-acting amylin analogue.
Analogue: A modified version of a natural molecule, changed to last longer or bind more strongly. Most therapeutic peptides are analogues.
B
Bac water: Short for bacteriostatic water: sterile water with benzyl alcohol added as a preservative, which allows repeated withdrawals from one vial.
Batch number: The code identifying one production run. A certificate of analysis only applies to the batch it names.
BDNF: Brain-derived neurotrophic factor, a protein involved in the growth and survival of nerve cells. Studies of Semax measure it.
BLA: Biologics License Application, the filing a company submits to the US FDA to ask for approval of a biologic.
BPC: Community shorthand for BPC-157, a 15 amino acid peptide derived from a stomach protein and studied mostly in animals.
C
Certificate of analysis (CoA): A lab report on a sample from a production batch, usually showing identity and purity. It describes the sample tested, not every vial sold. See the sourcing guide.
CJC: Community shorthand for CJC-1295, a modified GHRH. It comes in a short-acting form (no DAC) and a long-acting form (with DAC).
Cold chain: Keeping a product within a set temperature range from manufacture to use. In Philippine heat, the weak links are courier hubs, parked vehicles and brownouts.
D
DAC: Drug Affinity Complex, the albumin-binding modification that turns CJC-1295 from a short pulse into a signal lasting days.
Dead space: The liquid left in the needle and hub of a syringe after an injection. It is small but adds up over a vial.
Dual agonist: A drug that activates two receptors. Tirzepatide activates GIP and GLP-1 receptors.
Dysesthesia: An abnormal skin sensation such as tingling, burning or crawling. It was a notable adverse event in the retatrutide TRIUMPH-4 trial.
E
eGFR: Estimated glomerular filtration rate, a kidney function measure calculated from blood creatinine. See the bloodwork guide.
Endotoxin: A toxin from the cell walls of certain bacteria. It can cause fever and inflammation if injected, and it is not destroyed by the filtering that removes live bacteria.
F
FDA Philippines: The Food and Drug Administration of the Philippines, which registers medicines under RA 9711. A product not registered with it cannot legally be sold as a medicine.
G
Gastric emptying: The rate at which food leaves the stomach. GLP-1 drugs slow it, which drives both fullness and nausea.
GHRH: Growth hormone-releasing hormone, the hypothalamic signal that tells the pituitary to release growth hormone. Sermorelin, CJC-1295 and tesamorelin are GHRH analogues.
GHRP: Growth hormone-releasing peptide. A class that triggers GH release through the ghrelin receptor rather than the GHRH receptor. GHRP-2, GHRP-6 and ipamorelin belong here.
GIP: Glucose-dependent insulinotropic polypeptide, a gut hormone that boosts insulin release after meals. Tirzepatide targets its receptor.
GLP-1: Glucagon-like peptide-1, a gut hormone that increases insulin release, lowers glucagon, slows stomach emptying and reduces appetite. The target of semaglutide and the whole GLP-1 class.
Glucagon receptor: The receptor for glucagon, a hormone that raises blood sugar and increases energy use. Retatrutide and survodutide activate it alongside GLP-1.
H
Half-life: The time it takes for the level of a substance in the blood to fall by half. It largely sets how often a drug is given.
HbA1c: A blood test reflecting average blood sugar over roughly the previous three months. The standard marker for diabetes control.
HPLC: High-performance liquid chromatography, the lab method most often used to measure peptide purity.
I
IGF-1: Insulin-like growth factor 1, made mainly in the liver in response to growth hormone. The main blood marker for GH activity.
IM: Intramuscular, an injection into muscle. See subcutaneous vs intramuscular.
In vitro / in vivo: In vitro means in cells or tissue in a dish; in vivo means in a living animal or person. A result in vitro is the weakest level of evidence for an effect in people.
Injection-site reaction: Redness, itching, swelling or a bump where an injection went in. Usually mild and short-lived.
L
Lipohypertrophy: A rubbery lump of thickened fat under the skin from repeated injections in the same spot. Site rotation reduces it.
Lyophilised: Freeze-dried. Research peptides ship as lyophilised powder because it is far more stable than a solution.
M
Mass spectrometry: A lab method that measures molecular weight, used to confirm a peptide's identity.
mcg vs mg: 1 milligram (mg) equals 1,000 micrograms (mcg). Confusing the two is a tenfold error.
Multi-dose vial: A vial meant for several withdrawals. Once punctured, it should be dated; US CDC guidance is to discard within 28 days unless the manufacturer states otherwise.
O
Open-label: A trial in which participants and researchers know who is getting the drug. Easier to run, but more prone to bias than a blinded trial.
P
Peptide: A short chain of amino acids, usually up to about 50. Longer chains are generally called proteins.
Phase 1, 2, 3: Stages of human drug trials. Phase 1 tests safety in small groups, phase 2 tests dose and early efficacy, and phase 3 tests efficacy and safety in large populations before approval.
Pin / pinning: Community slang for injecting.
Placebo: An inactive treatment given to the comparison group in a trial, so the drug's effect can be separated from everything else.
Pulsatile release: Hormone release in bursts rather than a steady stream. Natural growth hormone is released this way, mostly during deep sleep.
R
Randomised controlled trial (RCT): A trial in which participants are randomly assigned to drug or comparison. The strongest single-study design for showing cause and effect.
Receptor: A protein on or in a cell that a signalling molecule binds to, triggering a response.
Reconstitution: Dissolving lyophilised powder in a measured volume of liquid. See the reconstitution calculator.
Research use only (RUO): A label meaning a product is sold for laboratory research, not registered as a medicine, and not evaluated for human use. It is a legal category, not a quality grade.
Reta: Community shorthand for retatrutide.
S
Secretagogue: Anything that causes a gland to secrete. A GH secretagogue makes the pituitary release growth hormone.
Sema: Community shorthand for semaglutide.
Somatostatin: The hormone that brakes growth hormone release. Its feedback is why GHRH analogues cannot push GH without limit.
Sterile water for injection: Water for injection with no preservative, meant for single use once opened.
Subcutaneous (sub-Q): An injection into the fat layer just under the skin. The route for most peptides and all GLP-1 pens.
T
TB: Community shorthand for TB-500, a synthetic peptide based on part of thymosin beta-4.
Tirz: Community shorthand for tirzepatide.
Titration: Starting a drug at a low dose and stepping up over time to limit side effects. GLP-1 labels use four-week steps. See the GLP-1 titration tool.
Triple agonist: A drug that activates three receptors. Retatrutide activates GIP, GLP-1 and glucagon receptors.
U
U-100 syringe: An insulin syringe calibrated so that 100 units equals 1 ml. Each unit is 0.01 ml. See the syringe units chart.
U-40 syringe: An older insulin syringe standard where 40 units equals 1 ml. Its markings do not match a U-100 syringe.